Triple valve for air-brakes.



PATENTED JAN. 20, 1903.

N. A. OHRISTENSEN. TRIPLE VALVE FOR AIR BRAKES.

APPLICATION FILED APR. 15, 1901.

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PATENTED JAN. 20, 1903.

N.A. CHRISTENSEN. TRIPLE VALVE FOR AIR BRAKES.

APPLIUATION FILED APR 15, 1901.

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Parent OFFICE.

OF MILW AUKEE, WISCONSIN.

TEMPLE VALVE FOR AIR-BRAKES.

$BPEGIFIGA'E3ZON forming part of Letters Patent N0. 718,911, datedJanuary 20, 1903.

Application filed April 15,1901. Serial No. 55,842, (W model.)

T 0 it whom it may concern.-

Be it known that I, NIELs ANTON CHRISTEN- SEN, a su bject of the King ofDenmark, residing at Milwaukee, in the county of Milwaukee and State oflVisconsin, have invented certain new and useful Improvements in TripleValves for Air-Brakes, of which the following isaspecification,reference being had to the accom panying drawings,forminga part thereof.

This invention relates to and consists of improvements upon triplevalves of the general kind shown and described in United States LettersPatent No. 580,846, granted to me April 20, 1897. i

The objects of these improvements are to confine the movement of themain piston within limits necessary to operate the main valve, to enablethe emergency-piston to open the emergency-valve without aid from themain piston, to balance the main valve, to insure a close fit andfreedom of movement of the main valve on its seat, to avoid leakagebetween the emergency-valve and its seat in case said valve is turned,and generally to improve the construction and operation of triple valvesof the kind to which my improvements relate.

It consists in certain novel features of construction and in thearrangement and combinations of parts hereinafter particularlydescribed, and pointed out in the claims.

In the accompanying drawings like characters designate the same parts inthe several figures.

Figure 1 is a vertical longitudinal section of a triple valve embodyingmy invention. Fig. 2 is a vertical cross-section thereof on the line 22, Fig. 1. Fig. 3 is a horizontal longitudinal section on the line 3 3,Fig. 1; and Fig. 4: is a vertical cross-section on the line 4 4, Figs. 1and 3.

a is the valve-case, formed in its larger end with a cylindricalpiston-chamber b and below it with a drip-chamber 0, having a neck orconnection d for the attachment of the train-pipe in the usual manner.At its larger end the valve-case is provided with a detachable cover 8,which is bolted thereto with an interposed gasketfand affords access tothe piston-chamber. It is formed with a passage g, which opens into thepiston-chamber b and communicates through a passage h with the upper endof the drip-chamber c. A bushing composed of inner and outer parts orcylinders i and j is fitted into a longitudinal opening in thevalve-case and extends from the piston-chamberb through the smaller endof said case, which is attached to and communicates with the auxiliaryreservoir and brake-cylinder through passages 7t and 1. Between theinner and outer parts 11 and of said bushing are formed longitudinalpassages 'm m and n n, which terminate at their inner ends toward thepiston-chamber b in concentric annular ports 0 and p. The passages m mopen laterally at their opposite ends into passages q q, formed in thevalve-case a, as shown in Figs. 3 and 4E. The passages q q communicatethrough a port controlled by a check-valve a" with the drip-chamber c,to which the train-pipe is attached. The passages n n communicate attheir ends opposite the port 19 with an annular enlargement of thepassage Z, leading to the brake-cylinder, as'shown in Fig. 1. The innerpart i of the bushing is formed in the under side with ports's,i,anda.Theportsopensintoanannular recess 1;, formed in the valve-case aroundpart i of said bushing, and communicates, as shown in Fig. 3, through alateral passage to with the atmosphere.

x is the main valve, which controls communication between thebrake-cylinder and the atmosphere and between the brake-cylinder and theauxiliary reservoir for releasing and making service applications of thebrakes. It is made of approximately D shapein crosssection and isloosely fitted in the inner part i of the bushing, the bore of which iscorrespondingly shaped by a drift. Said valve is formed through itsinner end with a longitudinal bore y, which at its opposite end opensthrough the face of the valve, so as to register with the port a whenthe valve is moved to the extreme right, as shown in Fig. 1. A cavityzis also formed in the face of said valve and arranged to connect theports 5 and if when the valve is moved to the extreme left for releasingthe brakes.

An annular winged piston 1 is fitted to Work in the chamber 1). Itisformed around its inner margin with a cylinder 2 and at the innor end ofsaid cylinder with an annular valve-back 3, in which is fitted apackingring 4, of hard rubber or other suitable material. The valve backor base 3 fitsloosely on the outer side into a rim 5 on the outer part jof the bushing, and a tubular extension or rim 6 on the inner margin ofsaid valve back or base fits'into a corresponding recess in the innerend of the innerpartt'of said bushing,

v thus forming restricted openings for the passage ofauxiliary-reservoir air from the piston-chamber b on the outside andfrom the interior of the inner part dot the bushing on the inside to theport 19 when said valve is opened. i

A piston 7, fitted to work in the cylinder 2 of the annular piston 1, isformed or provided with a stem 8, which is loosely fitted and movable alimited distance in a longitudinal groove in the back or upper side ofthe main valve 00 without effect upon said valve.

The stem 8 is formed with shoulders 9 and 10, adapted to engage with theends of the slide-valve a: and to move said valve after taking up theplay into release and service positions.

A bow-spring 11, attached to the upper side of said stem and bearingagainst the top of the inner part 7: of the bushing, holds the workingface of the valve 00 snugly against its seat. The valve is secured tosaid stem by a screw 12 passing through one side of the valve into aslot in one side of the stem, as shown in Fig. 3.

A needle graduating-valve 13, fitted in the port y of the valve 210 andhaving a seat at its inner end therein, is engaged by a head at itsouter end with a forked lug on the under side of the stem 8. Adjacent tosaid seat the valve .90 is formed with .lateral passages 14, openinginto the bore y, for admitting auxiliary-reservoir air into said boreand thence to the brake-cylinder through the port it and passages 77.and Z when the main valve 00 and the graduating-valve 13 are moved tothe ex-- treme right, as shown in Fig. 1.

To limit the main piston 7 to the movement required for serviceapplication of the brakes and prevent its further traverse by theoperation of the annular emergency-piston 1, said piston 7 is formedwith an annular rim 15, which serves by engagementwith the gasket f tostop said piston in its outward movement in the position in which it isshown in Figs. 1 and 3. The emergency-piston 1 is also formed on itsouter side near its inner and outer margins with annular ribs 16 and 17,which, with the rim 15 on the main piston and gasket f, serve when bothpistons are moved to the extreme right, as shown in Fig. 3, foremergency applications of the brakes to prevent the leakage of air fromthe auxiliary reservoir into the train-pipe in case the packing ofeither piston is defective.

The inner part 2' of the bushing is in open communication at both endsat all times with the auxiliary reservoir, so that the main valve m issubjected at both ends to the same pressure and is consequentlybalanced.

The usual leak-groove or restricted passage 18 for charging theauxiliary reservoir with compressed air from the train-pipe is formed inthe cylinder 2 of the emergency-piston 1, as shown in Fig. 1.

My improved triple valve, as hereinbefore described, operates asfollows: For making a service application of the brakes the usualreduction of pressure-say from five to six poundsis made in thetrain-pipe. When this occurs, the main piston 7 is shifted to the right,as shown in Fig. 1, by the greater pressure in the auxiliary reservoir.The initial movement of the piston 7 to the right unseats thegraduating-valve 13 and cuts off communication between the auxiliaryreservoir and train-pipe through the groove 18. The further movement ofsaid' piston in this direction causes the shoulder 9 on its stem toengage with the main valve 00 and shift it into the position in which itis shown in Fig. 1. Communication between the passage 1, lead ing to thebrake-cylinder and the atmosphere through the port If, cavity 2, port 3,recess o, and passage 10, is cut off, and the inner end of the passage 1controlled by the graduating-valve, is brought into register with theport a. Compressed air thereupon flows from the auxiliary-reservoirconnection through the openings 14:, passage 3 port u, and passages uand Z into the brake-cylinder. As soon as the pressure in the auxiliaryreservoir is reduced to or slightly below the reduced train-pipepressure the main piston 7 will be moved back to the left sufficientlyto close the graduating-valve 13, which is very sensitive in operation,and then stopped in a position to cut off communication between theauxiliary reservoir and train-pipe, as well as between the auxiliaryreservoir and brakecylinder. The pressure thus admitted to thebrake-cylinder will be considerably below that in the auxiliaryreservoir, and the brakes will be held applied with a forcecorresponding to the pressure in the brake-cylinder, while theconditions last-above stated remain unchanged. To apply the brakes withstill greater force, a further reduction from two to three pounds ismade in the train-pipe pressure, and the operations above explained willbe repeated. Thus the brakes may be applied with a gradually-augmentedforce until the pressures in the brake-cylinder and auxiliary reservoirare equalized.

To release the brakes, the train-pipe pressure is restored and acting inopposition to the reduced auxiliary reservoir pressure shifts the mainpiston 7 back to the left. The

shoulder 10 on the piston-stem engaging with the valve 50 carries thepassage y out of register with the port to and the cavity 2 over theports 8 and 25, through which air thereupon escapes from thebrake-cylinder to the atmosphere. At the same time communication isestablished through the groove 18 between the brake-cylinder and theauxiliary reservoir, and the latter is gradually re-.

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charged with compressed air until the pressure therein reaches that inthe train-pipe.

To make an emergency application of the brakes, an abnormalreduction-say from ten to twelve pounds-is made in the trainpipepressure. Nhen this occurs, the unbalanced auxiliary-reservoir pressureshifts both the emergency and main pistons l and 7 to the extreme right,as shown in Fig. 3. This cuts off communication between thebrakecylinder and the atmosphere and also between the auxiliaryreservoir and the train-pipe through the groove 18 and at the same timeunseats the emergency-valve t, uncovering the annular ports 0 and p. Theunbalanced pressure in the train-pipe will thereupon open thecheck-valve 'r, and air will rush from the trairrpipe through thepassages q and m, ports 0 andp, and passages 11 and l into thebrake-cylinder. The flow of air under higher pressure from the auxiliaryreservoir into the brake-cylinder will in the meantime be retarded bythe restricted openings between the rims of theemergenc-y-valve and therims on the bushing until the pressure in the brake-cylinder nearlyequals that in the train-pipe, whereupon the check-valve 1' will closeand the pressure in the brakecylinder will be augmented by the air underhigher pressure thus held back in the auxiliary reservoir. Train-pipeair vented at an abnormally reduced pressure into the brake-cylinder, asabove explained, will as sist in applying the brakes, and the furtherreduction in train-pipe pressure thus pro duced will cause all thetriple valves con nected with the same train'pipe to operatesimultaneously or in quick succession. After the pressure in thebrake-cylini'ler equals the reduced train-pipe pressure and thecheckvalve r is closed, air under higher pressure will continue to flowfrom the auxiliary reservoir into the brake-cylinder until the pressurestherein are equalized. Thus the most powerful application of the brakespossible is made simultaneously or in quick succession on all the carsof a long train.

By restoring the normal pressure in the train-pipe the moving parts ofthe valve mech anism will be restored to their original positions, so asto release the brakes and recharge the auxiliary reservoir.

A slide-valve having a flat face fitted to a flat seat has been found inpractice more satisfactory than a piston-valve, because it works withgreater freedom and certainty and is less liable to leak. By terminatingthe passages m and n in continuous annular ports indentation of thepacking-ring 4 of the emergencyvalve, such as would cause it to leak ifit were turned or shifted, which is liable to occur, is avoided. Theemergency-piston 1 is made of sufficient area to operate theemergency-valve without aid from the main piston 7, so that in case themain piston should stick in its cylinder 2 and fail to respond to theusual reduction in train-pipe pressure for service application of thebrakes the emergency-valve would still be operated by theemergency-piston upon making a greater reduction in the train-pipepressure. The main piston is accordingly provided with astop by which itis limited to the traverse necessary for making service applications ofthe brakes, and any extra or unnecessary movement thereof by theemergency-piston in making emergency applications of the brakes isavoided.

It will be observed that the emergencyvalve is so arranged with relationto the main piston that in case the latter should stick in the cylinder2 or fail for other reasons to operate in response to the usualreduction of pressure forservice applicationsit would upon a furtherreduction of pressure being made be shifted by the emergency-piston farenough to the right, as shown in Fig. 1, to cause the main valve 00 toclose the exhaust-port and cut off the escape of air from thebrake-cylinder to the atmosphere. It will be observed also that when theparts of the valve are in release and running position theemergencyvalve 4 will be exposed on one side to atmospheric pressure toan extent equal at least to the area of the annular port p, while on theother side its entire area will be exposed to auxiliary-reservoirpressure. As these areas which are exposed under the conditions assumedto different pressures are constant factors, a predetermined reductionof trainpipe pressure will be required to unseat the emergency-valve andeffect an emergency application of the brakes, and the emergencyvalvewill be held positively against its seat by the unbalancedauxiliary-reservoir pressure upon it until such predetermined reductionin train-pipe pressure is made or until the auxiliary-reservoir andbrake'cylinder pressures are equalized in applying the brakes with thegreatest available force. Under the last-mentioned condition of balancedauxiliary-reservoir and brake-cylinder pressures there will be nopreponderance of pressure tending to unseat the emergency-valve, and thebrakes being applied with full force it is immaterial whether saidvalveis held tightly closed or not. A spring for holding the emergency-valveto its seat is thus rendered unnecessary and is therefore dispensedwith.

Various changes in minor details of construction and in the arrangementof parts may be made Without departing from the principle and intendedscope of my invention.

I claim- 1. In a triple valve for air-brakes, the com bination of avalve-case provided with annular ports communicating respectively withthe train-pipe and brake-cylinder, a valve normally closing said ports,and a piston for operating said valve, substantially as described.

2. In a triple valve for air-brakes, the combination of a valve-casehaving annular ports communicating respectively with the train- IIO pipeand brake-cylinder connections, a main valve controlling communicationbetween the brake-cylinder and auxiliary-reservoir connections andbetween the brake-cylinder and the exhaust-port,an annularemergency-valve normally closing said annular ports, an annular pistonfitted to Work in said case and connected with said emergency-valve, andan independently-movablemain piston fitted to Work in said annularpiston and connected by a stem which passes through said annularemergency-valve with the main valve, substantially as described.

3. In a triple valve for air-brakes, the combination of a valve-casehaving a piston -chamher and train-pipe and auxiliary-reservoirconnections communicating with opposite ends of said chamber, a bushingextending longitudinally through said case, communieating at the endswith said chamber and with the auxiliary reservoir, and havinglaterally-opening ports communicating with the brake-cylinder and withthe atmosphere, and annular ports at its inner end opening into thepiston-chamber and communicating respectively with the train-pipe andwith the brake-cylinder, a main valve fitted in said bushing andcontrolling communication between the lateral ports therein, an annularemergency-valve normally closing the annular ports at the inner end ofsaid bushing, an annular emergency-piston fitted to work in saidpiston-chamber and connected with said annular valve, a main pistonfitted to work in said annular piston and loosely connected by a stempassing through the emergencyvalve with the main valve, and agraduatingvalve controlling a port in the main valve and vconnected withthe main piston, substantially as described.

4. In a triple valve for air-brakes, the combination of a valve-casehaving a piston-chamber and train-pipe and auxiliary-reservoirconnections communicating respectively with opposite ends of saidchamber, a bushing extending from said chamber through one end of saidcase and having laterally opening ports communicating with thebrake-cylinder and with the atmosphere and ports at its inner endopening into the pistonchamber and communicating respectively with thetrainpipe and with the brake cylinder, a main valve fitted in saidbushing and controlling communication between the brake-cylinder and theauxiliary reservoir and between the brake-cylinder and the atmosphere,an annular emergency-valve loosely fitting into the end of said bushingand normally closing the ports at its inner end, a rim on said bushingextending, over said "alve, and a rim on said valve extending into saidbushing and forming restricted openings for the passage ofauxiliary-reservoir air to the brake-cylinder when said valve is opened,an annular piston fitted to work in said piston-chamber and connectedwith said emergency-valve, and an independently-movable piston fitted insaid annular piston and connected with the main valve, substantially asdescribed.

5. In a triple valve for air-brakes, the combination of a valve-casehaving a piston'chamher and train-pipe and auxiliary-reservoirconnections communicating respectively with opposite ends of saidchamber, an annular piston fitted in said chamber and formed withannular ribs on the end toward the train-pipe connection, a pistonfitted within said annular piston and formed on the end toward thetrain-pipe connection with an annular rim, the train-pipe connectionopening into said chamber through ports, one between the annular ribs onthe annular piston and the other within the radius of the annular rim onthe other piston,a main valve connected with the inner piston, and anemergency-valve connected with the annular piston, substantially asdescribed.

In witness whereof I hereto affix my signature in presence of twoWitnesses.

NIELS ANTON CHRISTENSEN.

Witnesses:

CHAS. L. Goss, C. M. BOTTUM.

